1/* $OpenBSD: tfork_thread.S,v 1.6 2016/05/07 19:05:21 guenther Exp $ */ 2/*- 3 * Copyright (c) 2000 Peter Wemm <peter@FreeBSD.org> 4 * Copyright (c) 2003 Alan L. Cox <alc@cs.rice.edu> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29#include <machine/asm.h> 30#if 0 31__FBSDID("$FreeBSD: /repoman/r/ncvs/src/lib/libc/amd64/gen/rfork_thread.S,v 1.1 2003/10/13 20:32:33 alc Exp $"); 32#endif 33 34/* 35 * With thanks to John Dyson for the original version of this. 36 */ 37 38#include "SYS.h" 39 40/* 41 * %rdi %rsi %rdx %rcx 42 * __tfork_thread(param, psize, start_fnc, start_arg); 43 * 44 * param: Argument to pass to the actual kernel call. 45 * psize: Other argument to pass to the actual kernel call. 46 * start_fnc: Address of thread function to call in child. 47 * start_arg: Argument to pass to the thread function in child. 48 */ 49 50ENTRY(__tfork_thread) 51 movq %rdx, %r8 52 movq %rcx, %r9 53 54 /* 55 * Prepare and execute the thread creation syscall 56 */ 57 movl $SYS___tfork, %eax 58 syscall 59 jb 2f 60 61 /* 62 * Check to see if we are in the parent or child 63 */ 64 cmpl $0, %eax 65 jz 1f 66 ret 67 68 /* 69 * If we are in the child (new thread), then 70 * set-up the call to the internal subroutine. If it 71 * returns, then call __threxit. 72 */ 731: 74 movq %r9, %rdi 75 call *%r8 76 77 /* 78 * Thread exit system call 79 */ 80 movl $SYS___threxit, %eax 81 xorl %edi, %edi 82 syscall 83 84 /* 85 * Branch here if the thread creation fails: 86 */ 872: 88 SET_ERRNO 89 ret 90END(__tfork_thread) 91